------- Comment #6 from steven at gcc dot gnu dot org 2010-07-18 17:29 ------- Smaller hand-changed assembly without new bundle (left aborts, right does not):
.global f1# .global f1#
.type f1#, @function .type f1#, @function
.proc f1# .proc f1#
f1: f1:
.prologue .prologue
.body .body
.mmi .mmi
mov r15 = r12 mov r15 = r12
nop 0 nop 0
mov r14 = r12 mov r14 = r12
;; ;;
.mmi .mmi
st8 [r15] = r32, 8 st8 [r15] = r32, 8
;; ;;
st8 [r15] = r33, -4 st8 [r15] = r33, -4
nop 0 nop 0
.mii | ;;
> .mmb
> st4 [r15] = r34
> ;;
ld8 r8 = [r14], 8 ld8 r8 = [r14], 8
nop 0 <
;; ;;
nop 0 nop 0
.mmb .mmb
ld8 r9 = [r14] ld8 r9 = [r14]
st4 [r15] = r34 | nop 0
br.ret.sptk.many b0 br.ret.sptk.many b0
.endp f1# .endp f1#
The only thing that seems to matter, is that "st4 [r15] = r34" comes before
"ld8 r9 = [r14]".
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43494
